Here's my partial understanding of Dave's explanation of how time works in the GURPS campaign. There is a prime timeline, of which the good guys (which I'll call Far and Away Time Travel, FATT) and bad guys (which will be called One True Timeline Only, OTTO) are aware of and exist in. Someone invented time travel and somehow changed history. Instead of changing the prime timeline the change created a divergent timeline. With more research scientists found out that any significant change in a timeline creates another timeline.

But now there are all these divergent timelines. With more research they find out that some timelines are more "good" or "evil" than others. More importantly, the good and evil vibes are causing ripples that affect the prime timeline, subtly changing it more towards good or evil. One group of scientists decide that this is a golden opportunity: by making more good realities, they will make their world more good. So off they go and start to create more realities.

Another group of scientists finds out what FATT is doing. Horrified by the implications, they decide that the only way for the prime timeline inhabitants to regain their own self determination (and not be influenced by the good and bad vibes of other timelines) is to somehow eliminate the divergent timelines. But how to do that, when every change in one timeline creates a divergent timeline?

But there is a way, and after months of hard work, OTTO scientists discovered the solution: a way to converge and combine two timelines. With enough patience and with a little luck, OTTO may be able to converge all the timelines back into the prime timeline in a few years. But not if FATT continues to diverge and create more timelines.

So the solution is simple after all: eliminate FATT. Destroy their headquarters and bases, deprive them of their resources and time travel equipment. Kill every time agent, for only time travelers have the ability to change history and create divergent timelines. Subsequently, OTTO has finally started targetting FATT installations, sparking a war that rages across the timelines.

Most of the preceding explanation I made up since I didn't quite understand Dave's explanation. We spent a good 15 minutes taking Dave's theories apart, which is more bent towards creating good and bad timelines, like some kind of weird competition. But if that's the case then it just seems to create a big mess. What's the point of stopping evil? You'll get two timelines, one where the evil was stopped and one where it wasn't stopped. With hundreds or even thousands of timelines out there an extra timeline is not going to change the balance of good or evil in any noticeable way. And if it does then one side would have one a long time ago by making a few hundred more good/evil timelines than the other.

Dave's big mistake was trying to explain all this to us. We were just happy to go along and do good, knowing that our efforts were helping in some undefined way. But now the bad guys are only trying to make everything like it was: one timeline. That doesn't seem so bad, even if you have to destroy all the other timelines. If you have a problem with that then why don't you have a problem with creating more timelines? It's tantamount to cloning as far as I can tell, and a serious violation of a whole universe's right to privacy and self- determination.

In any case, that leaves me with the unenviable task of creating my adventure under Dave's world view...